/*
 * Copyright (c) 2011-2012 Alexander Dubu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * o  Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * o  Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * o  Neither the name Axil nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package axil.framework.resource;

import java.io.*;

import static axil.framework.Functions.abort;
import static axil.framework.Functions.empty;


/**
 * A resource loader that loads resources directly from the Jar itself. This
 * resource loader is entirely optional. At build time, all of the Axil
 * resources are copied into the directory where this class resides so that they
 * are embedded in the Jar file.
 */
class EmbeddedResourceLoader implements ResourceLoader {
	private String root;


	EmbeddedResourceLoader(String root) {
		assert ! empty(root);
		this.root = root;
	}


	/**
	 * Get a stream for the named resource. The resource name contains the
	 * relative path for the resource, such as "data/axil.cfg". A null value
	 * is returned if the resource cannot be loaded by this object.
	 */
	public Reader reader(String name) {
		Reader stream = null;
		InputStream in = this.getClass().getResourceAsStream(root + '/' + name);
		if (in != null) {
			try {
				stream = new BufferedReader(new InputStreamReader(in, "UTF-8"));
			} catch (UnsupportedEncodingException e) {
				throw abort(e);
			}
		}
		return stream;
	}


	/**
	 * Return a string representation of this object. The string returned is
	 * never null.
	 */
	public String toString() {
		return "Embedded at " + root;
	}
}
